Evoke
®
SCS System Clinical Manual
CLIN-UMAN-005175
Revision: 9.00
Page 41 of 101
C)
D)
E)
Figure 7.4: Measurement electrode scan window showing: A) 4 electrode configurations, SQI
values and Settings button; B) Scan stopped; C) ‘-’ indicates not enough stimuli to calculate
SQI, grayed slots indicates that the scan is disabled; D) SQI = 0% indicates no ECAP has been
detected, blank slot indicates there is no valid scan configuration available; E) colored bar
indicates the electrode configurations that are plotted on the ECAP display.
7.4.1
ECAP and artifact estimation
The signal recorded by the CLS or eCLS is a combination of the ECAP, artifact from the
stimulation pulse, and background electrical or neural noise. The artifact is a signal resulting
from the stimulus pulse that is not related to neural activity, but can interfere with
measurement of an ECAP.
The CPA estimates the ECAP and artifact from the recorded signal so that an ECAP estimate
may be displayed with the artifact and noise removed (see Section 7.4.1.1) and the quality of
the ECAP may be calculated (see Section 7.4.2).
7.4.1.1
ECAP display
The ECAP display shows signals from up to 4 measurement configurations represented by 4
colors. The display shows the ‘latest’ from one stimulation pulse, ‘average’ from 16 stimulation
pulses and an ‘estimate’ calculated from the latest or average signals.
1.
Touch an electrode configuration slot on the measurement electrode scan window to
turn the ECAP display off or on for that configuration (see Figure 7.4E).
2.
Touch the ECAP display to toggle between three modes of ECAP display (see Figure 7.5):
Raw, Scrubbed (simple) and Scrubbed (detailed).
